Alright, let me acknowledge the folks who say RPF1s should run without caps. I am not one of those people - although I agree those ones you get from Enkei do look pretty odd sticking way out. Nonetheless my hubs are 50% rust by volume and look awful and I really like my old JCW caps.

So I modeled the two wheel openings and printed an adapter ring. This version worked alright, but needs a bit of tweaking - it's a little loose in the wheel and doesn't clear the rear hubs (which appear a millimeter smaller than the fronts, for some reason). Anyhow, once I have the design finalized I'll be posting the files if people are interested in printing their own. Here's a preview:

 

I prefer my wheels naked without center cap to save 0.001 kg. So what I like the most is the yellow Pac-man on the tire. So apt to indicate the correct tire rotation.

 

I would cover the center rings with a little Rust Converter to clean the area up and give it a slight black hue.

But I agree the cool factor is the Pac Man is pretty cool.

Motor On!

 

Me like subtle subversion.

I went and checked my new yet to be mounted RE71Rs and each has the yellow dot, though they won't last a few track daze.

 

Share the file! Cool stuff.

 

Alrighty, the experiment ended in a failure - mostly because the material I used got too soft at the temperature the wheel gets. Ended up losing two caps on the highway. Something with the higher Tg or adding an expansion ring would probably fix that, but I'm done experimenting for now.

Here's the files if anyone wants to try them out. It fits nice and snug when cold and clears the gap to the hubs front and rear.

rpf1_ring.zip